Method of producing bonded textile fabrics with improved dimensional stability

ABSTRACT

A METHOD IS PROVIDED FOR PRODUCING A BONDED TEXTILE FABRIC WITH IMPROVED LAUNDERING AND DRY CLEANING DIMENSIONAL STABILITY IN WHICH A COMPOSITE COMPRISED OF AT LEAST TWO PLIES OF THE SAME OR DIFFERENT TEXTILE FABRICS WITH THE PLIES BONDED TOGETHER BY AN UNCURD TO PARTIALLY CURED ADHESIVE BEING COMPACTED AND THEN COMPLETELY CURED. THE BONDED TEXTILE FABRICS OF THIS INVENTION ARE ESPECIALLY USEFUL IN THE MANUFACTURE OF WEARING APPAREL, BUT ALSO FINE USES IN HOME FURNISHINGS AND INDUSTRIAL FABRICS.

, March 27, 1973 J, BAUER 3,723,217

METHOD OF PRODUCING BONDED TEXTILE FABRICS WITH IMPROVED DIMENSIONALSTABILITY Filed July 11, 1969 a, v a: 1

I/VVW7'0K JAC KSO N BAu ER United States Patent O 3,723,217 METHOD OFPRODUCING BONDED TEXTILE FABRICS WITH IIVIPROVED DIMENSIONAL STABILITYJackson Bauer, Croydon, Pa., assignor to Collins and Aikman Corporation,New York, N .Y. Filed July 11, 1969, Ser. No. 841,042 Int. Cl. 1332b31/08 US. Cl. 156-464 6 Claims ABSTRACT OF THE DISCLOSURE A method isprovided for producing a bonded textile fabric with improved launderingand dry cleaning dimensional stability in which a composite comprised ofat least two plies of the same or different textile fabrics with theplies bonded together by an uncured to partially cured adhesive beingcompacted and then completely cured. The bonded textile fabrics of thisinvention are especially useful in the manufacture of Wearing apparel,but also find uses in home furnishings and industrial fabrics.

BACKGROUND OF THE INVENTION (1) Field of the invention This inventionrelates to the method of producing bonded textile fabrics. Moreparticularly, this invention is concerned with the method of producingbonded textile fabrics having improved laundering and dry cleaningdimensional stability which are comprised of at least two plies of atextile fabric.

DESCRIPTION OF THE PRIOR ART well known methods. One method is to use acurable bonding agent such as an acrylic or urethane adhesive. Anothermethod is to use a ply of a foam such as a polyesterurethane foam and bythe flame laminating method, completely collapse the foam so that itbecomes the adhesive.

Bonded textile fabrics have many properties which make them especiallyuseful for certain applications. The ability to bond an outer wearfabric to a lining fabric to make a self lined bonded fabric make thebonded fabrics especially useful in apparel application.

Bonded textile fabrics would be more extensively employed except for thefact that the bonded textile fabrics heretofore available hadnotoriously poor dimensional stability especially to home laundering anddry cleaning. It was not uncommon for the prior art, bonded textilefabrics, to shrink to 15% after being laundered. In addition to theoverall shrinkage of the bonded fabrics, the various plies comprisingthe bonded textile fabric tended to shrink at different rates whichfurther caused the bonded fabrics to buckle or pucker which was highlyundesirable.

Various methods have been suggested by the prior art to improve thedimensional stability of conventional single ply textile fabrics. Onemethod which has proven to be especially useful is compacting. Themethods of compacting are well known to those skilled in the art "iceand are disclosed in patents such as Walton US. Pat. 2,765,513.

The methods of compacting conventional textile fabrics have not,however, proven to be successful in the manufacture of bonded textilefabrics. Attempts to compact the individual plies comprising the bondedfabric before bonding did not sufficiently increase the dimensionalstability of the final product. The textile fabrics were difiicult tomaintain in the compacted state because the textile fabrics that aregenerally employed to make bonded textile fabrics are of a loose openconstruction which does not readily hold compacting. A further problemencountered was that each type of fabric employed had a differentshrinkage and accordingly each had to be compacted a different amount.However, the fabrics when bonded together did not necessarily shrink thesame amount as when unbonded and accordingly, some buckling andpuckering still occurred. An additional problem encountered was that theprocess steps involved in bonding pulled out a considerable amount ofthe compaction before bonding occurred. A further objection tocompacting the plies before bonding was that it was not economicallyfeasible because of the additional processing cost involved incompacting each ply before lamination.

Attempts to compact the bonded textile fabrics after bonding and curingwere not completely satisfactory in that the fabrics would not retain asufiicient amount of compaction to control the dimensional stabilityduring laundering and dry cleaning.

It is accordingly, a primary object of this invention to provide bondedtextile fabrics having improved laundering and dry cleaning dimensionalstability.

It is a further object of this invention to provide a process for themanufacture of bonded textile fabrics which have improved dimensionalstability to laundering and dry cleaning.

Other objects and advantages of this invention will become furtherapparent from a review of the drawings and subjoined specification andclaims.

SUMMARY OF THE INVENTION In accordance with the present invention,bonded textile fabrics having improved dimensional stability areobtained by compacting a composite comprising of at least two plies oftextile fabrics in which the plies are bonded together by uncured topartially cured adhesive and then fully curing the composite to form thebonded textile fabrics.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration ofa compactor through which a composite comprised of a woven fabric, and aknitted fabric is shown being processed.

FIG. 2 is an enlarged cross sectional illustration of an uncompactedcomposite.

FIG. 3 is an enlarged cross sectional illustration of the compactedcomposite.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The initial step in the processof the present invention is the preparation of the starting composite.The starting composite is comprised of at least two plies of the same ordifferent textile fabrics and the plies are bonded together by uncuredto partially cured adhesive.

The textile fabrics that are used to make the composites aresubstantially identical to the fabrics employed by the prior art to makebonded textile fabrics, with the exception that somewhat lighter weightgoods can be employed since the compacting will increase the weight perlineal yard of the goods. The fabrics may be knitted, Woven or nonwovenin construction and may be comprised of natural lfibers such as cottonor wool, regenerated fibers such as viscose rayon, synthetic fibers suchas acetate rayon, polyamides or polyesters or blends of these fibers.

The starting composite may be comprised of more than two plies oftextile fabrics. However, in general, it is preferable to employ only aface ply of one type of textile fabric, such as a woven fabric and abacking ply of another type of textile fabric, preferably a knittedtricot fabric.

The adhesive that is employed to make the composite is a criticalcomponent of the laminate. The adhesive that is selected should hold theplies of the composite together during the initial processing steps andduring compacting. The adhesive in the uncured to partially cured statemust have sufficient flowability that the adhesive bonds placed underexcessive stress by compacting will fiow into positions where when thecure of the adhesive is completed, they will hold the plies together inthe new configuration imparted by the compacting step. The adhesiveshould also be curable to a form wherein it will not be substantiallyaffected by either dry cleaning or laundering. The ideal adhesive shouldhave green tack, that is, it should have a sufiicient adhesiveness inthe uncured state that it will hold the plies together. However, it ispossible to use adhesives which have to be partially cured in order toprovide sufficient adhesion to hold the plies together. Liquid adhesivesare most useful in the manufacture of the starting composite. Adhesivesmay be of the water dispersible types such as the aqueous dispersions ofthe acrylic polymers or may be of the solvent dispersed types such asthe solvent solutions of the urethane adhesives. The adhesives areapplied in the conventional manner, for example one or both of theadjoining surfaces of the plies are treated with a solution of theadhesive and then the adhesive is dried to a point where it acquires asufiicient tack to hold the plies together. The textile fabric plies arethen brought into contact to form the composite. Care is taken in thebonding step to limit as much as possible the advancement of the cure ofthe adhesive.

When a ply of a polyesterurethane foam is used as the adhesive bycollapsing the foam by the flame method, it should be noted that whenthe urethane is thermally degraded isocyanate linkages form. Theisocyanate linkages are believed to form bonds with the fibers. Theisocyanate due to exposure to hydroxyl groups for example the watervapor of the air, reforms into a urethane. During the period ofreformation, the degraded material is in fact an uncured to partiallycured adhesive.

The starting composite prepared as indicated above is fed into acompactor 12. The compactor 12 which is schematically illustrated inFIG. 1 is comprised of a feed roll 14 and a retarding roll 16, a fabricindenter 18 and a steam heated shoe 20. The feed roll 14 is driven so asto have predetermined peripheral speed. The retarding roll 16 is drivenso as to have a peripheral speed which is less than the speed of thefeed roll 12. In addition, the surface of the retarding roll is somewhatroughened as by mild etching or metallic spray coating, so that it willgrip the composite 10 with greater frictional force than the feed roll14, at the nip 22 of the feed roll 14 and the retarding roll 16. Thespeed of advancement of the composite 10 is decelerated from theperipheral speed of the feed roll 12 to the peripheral speed of theretarding roll 14 because of the greater gripping effect of theretarding roll 14 on the composite 10. The fabric indenter 18 is anelongated bar which extends across the width of the compactor parallelto the nip 22 of the feed roll 14 and retarding roll 16. The fabricindenter 22 prevents a substantial portion of the compacting forcesimparted to the composite 10 by the difference in speeds of the feedroll 14 and the retarding roll 16 from being fed into the sec tion ofthe composite which is rearward of the forward edge of the fabricindenter 18. The fabric indenter 18 is spaced from the nip 22 at apredetermined distance. The area between the fabric indenter 18 and thenip 22 is a deceleration zone wherein the compacting of the composite 10occurs. The steam heated shoe 20 is used to preheat the composite beforecompacting.

In the compacting process, the composite 10 which is in frictionallyrestrained engagement with the retarding roll 16 is prevented fromadvancing at the same rate as the rate of speed of the feed roll 14.This causes the composite 10 to expand in directions normal to thedirection of advancement, thereby causing the composite 10 to becomecompacted. The speed of the feed roll 14, the retarding roll 16 and thelength of deceleration zone are selected so as to compact the compositeto a predetermined amount without causing detrimental buckling of thecomposite 10 in the compacting process. It is, of course, possible toselect the speeds of the feed roll 14 and the retarding roll 16 and thelength of the deceleration zone so as to cause a certain amount ofcontrolled pleating in wherein this is desired to obtain a decorativeeffect in the final bonded textile fabric. The present process is notlimited to any one particular type of compactor, however, it has beenfound that the compactors of the type disclosed by R. R. Walton in US.Pat. 2,765,514 are particularly useful in the process of this invention.Since the actual mechanics of the operation of a compactor are to someextent dependent on the particular type of compactor employed and arewithin the knowledge of those skilled in the art, additional details onthe actual operation of the compactor are not necessary.

It should be carefully noted that the effect of compacting on thecomposite 10 is quite different from the effect of compacting on aconventional single ply textile fabric. This can be seen by reference toFIGS. 2 and 3. The starting uncompacted composite 10 illustrated in FIG.2 has a face ply 24 of a woven textile fabric and a backing ply of aknitted fabric 26. The plies 24 and 26 of the uncompacted composite 10are joined by an uncured to partially cured resin 28. As the composite10 is advanced through the deceleration zone between the fabric indenter18 and the nip 22, the composite 10 is compacted which causes the pliesof the composite 10 to expand in directions normal to the direction ofadvancement indicated by the arrow in FIG. 3. The expansion indirections normal to the direction of advancement is obtained becausethe plies comprising the composite are formed by the compacting forceinto a curved fan-fold configuration as is illustrated in FIG. 3. It canbe appreciated from the illustration in FIG. 3 that the outwardly curvedsurfaces of each ply are stretched somewhat by the compacting step,while the inwardly sections of each ply are somewhat compressed by thecompacting step. This change in the surface area of the plies causesstrains to be placed upon the initially bonded areas of the uncuredcomposite. If the strain on the uncured bonds is excessive, the bondswill flow and because an uncured to partially cured adhesive isemployed, the adhesive will flow into a configuration wherein it willtend to hold the laminate in the compacted form. When the adhesive isthen fully cured, the fully cured bonds hold the bonded textile fabricin the compacted form.

The problem of both compacting the individual plies and realigning ofthe bonds between the plies is not encountered when compacting aconventional single ply textile fabric. However, when it was attemptedto compact the fully cured bonded textile fabrics of the prior art, thebonds which were fully cured before compacting caused the fabric toresist compacting. Furthermore, even after fabrics were compacted, thepresence of the cured bonds which were placed under stress by compactingtended to cause the fabrics to return to the uncompacted form. Thisshould be compared to the process of the present invention wherein thebonds placed under stress by compacting flow so as to hold the bondedtextile fabrics in the compacted form.

The amount of compacting to which the composite is subjected depends toa large extent on the desired dimensional stability to laundering anddry cleaning required in the final bonded textile fabric. 'Even arelatively small amount of compacting of the uncured composite willincrease the laundering and dry cleaning dimensional stability of thecured bonded textile fabric to some extent. It is preferable, however,to compact the composite in an amount at least sufiicient to compensatefor a substantial portion of the inherent laundering and dry cleaningdimensional instability of the bonded textile fabric. In this regard, itshould be noted that bonded textile fabrics exhibit a shrinkage which isnot necessarily a composite of the shrinkages of the various pliescomprising the bonded textile fabric. Accordingly, in order to evaluatethe amount of compacting which should be imparted to a given bondedtextile fabric, the fabric should be completely cured in the uncompactedform and then subjected to the various tests for which dimensionalstability is required such as dry cleaning and laundering. The uncuredcomposite should be compacted in an amount at least sufiicient tocompensate for the inherent dimensional instability of the uncompactedbonded textile fabric plus an additional amount to compensate for theunavoidable loss of compacting caused by handling during processing. Inthis regard, it should be noted, however, that in general a shrinkage ofup to 3% in either length or width is not considered to beobjectionable. It should be further noted that it is possible to compacta bonded textile fabric in an amount considerably greater than theamount required to compensate for the inherent shrinkage of the bondedtextile fabric and thereby obtaining a bonded fabric with stretchproperties. It is further possible to compact the bonded fabric so as toform decorative pleating or folds in the final bonded textile fabric.

After the composite has been compacted, it is cured to fully set thebonded fabric in the compacted form. The method of curing employed isdependent on the particular type of adhesive used. With an adhesive suchas the urethanes, it is possible for example, simply to roll up thefabric directly off the compactor and keep it in the rolled form forseveral days at room temperatures whereupon the adhesive will cureitself. It is also possible to use heat cured adhesives, such as theacrylics wherein the fabric is subjected to a heat treatment after thecompacting so as to set the fabric in the compacted form.

The method described above for obtaining dimensionally stabilized bondedtextile fabrics can be modified without departing from the scope of thepresent invention, for example other types of compactors can be employedthan the type schematically illustrated in FIG. 1. In addition, thecompacting step can be combined with other processes. For example, avariation of the above described method which has been proven to beespecially valuable is to employ as one of the fabrics a heat settablematerial such as a polyamide knitted fabric. The uncured composite iscompacted as described above in an amount considerably greater than theamount required to compensate for the inherent shrinkage of the bondedtextile fabric. The compacted composite is then subjected to a heattreatment sufiicient to both cure the adhesive and set the heat settablefabric whereby a stretchable, dimensionally stabilized bonded textilefabric is obtained.

What is claimed is:

1. The method for producing a bonded textile fabric with improveddimensional stability comprising: bonding at least two plies of textilefabrics together with an effective amount of an uncured to partiallycured adhesive to provide a composite, said effective amount beingsufficient to hold said plies together in a compacted configuration whenfully cured; compacting said composite in an amount sufficient to atleast compensate for a substantial portion of the laundering and drycleaning dimensional instability of said bonded textile fabric in theuncompacted state; and thereafter curing said adhesive, wherein saidcompacting comprises positively advancing said composite from a firstsurface at a first speed toward a second surface separate from saidfirst surface traveling at a second slower speed and carrying saidcomposite into frictionally restrained engagement with said secondsurface, said composite passing through a deceleration zone of apredetermined length immediately prior to engagement with said secondsurface, said first and second speeds and predetermined length of saiddeceleration zone being related so as to cause said composite to expandin directions normal to and thereby be compacted in the direction ofadvancement.

2. The process according to claim 1 wherein said composite is comprisedof a facing ply and a backing ply bonded directly together by an uncuredto partially cured adhesive.

3. The process according to claim 2 wherein at least one of said textilefabrics is a knitted fabric.

4. The process according to claim 2 wherein at least one of said fabricsis a woven fabric.

5. The process according to claim 2 wherein at least one of said fabricsis comprised of a thermally settable fibrous material selected from thegroup consisting of polyamide and polyester and said composite iscompacted in an amount in excess of the amount required to compensatefor the dimensional instability of the bonded textile fabric when in theuncompacted state and thereafter said composite is heated to atemperature sufficient to heat set said fibrous material, whereby astretch [bonded textile fabric is obtained.

6. The process according to claim 2 wherein said adhesive ispolymerizable acrylic or urethane resin.

References Cited UNITED STATES PATENTS 2,235,682 3/ 1941 Hawley 156-1643,255,061 6/1966 Dobbs l61159' X 3,558,393 1/1971 Bolliard et al. 1561812,825,117 3/1958 Evans et al. 2669 3,100,925 8/1963 Messinger 2-6--18.63,252,848 5/1966 Borsellino \156307 3,359,156 12/1967 Freuler et al.162--36l 3,409,960 11/1968 Dusenbury et al. 2876 3,471,907 10/1969Beckers 26-186 BENJAMIN R. PA'DGE'IT, Primary Examiner E. A. MILIJER,Assistant Examiner U.S. Cl. X.R.

